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<div class="titlepage"><div><div><h3 class="title">
<a name="boost_asio.reference.IoObjectService"></a><a class="link" href="IoObjectService.html" title="I/O object service requirements">I/O object service
      requirements</a>
</h3></div></div></div>
<p>
        An I/O object service must meet the requirements for a <a class="link" href="Service.html" title="Service requirements">service</a>,
        as well as the requirements listed below.
      </p>
<p>
        In the table below, <code class="computeroutput">X</code> denotes an I/O object service class,
        <code class="computeroutput">a</code> and <code class="computeroutput">ao</code> denote values of type <code class="computeroutput">X</code>,
        <code class="computeroutput">b</code> and <code class="computeroutput">c</code> denote values of type <code class="computeroutput">X::implementation_type</code>,
        and <code class="computeroutput">u</code> denotes an identifier.
      </p>
<div class="table">
<a name="boost_asio.reference.IoObjectService.t0"></a><p class="title"><b>Table 24. IoObjectService requirements</b></p>
<div class="table-contents"><table class="table" summary="IoObjectService requirements">
<colgroup>
<col>
<col>
<col>
</colgroup>
<thead><tr>
<th>
                <p>
                  expression
                </p>
              </th>
<th>
                <p>
                  return type
                </p>
              </th>
<th>
                <p>
                  assertion/note<br> pre/post-condition
                </p>
              </th>
</tr></thead>
<tbody>
<tr>
<td>
                <p>
                  <code class="computeroutput">X::implementation_type</code>
                </p>
              </td>
<td>
              </td>
<td>
              </td>
</tr>
<tr>
<td>
                <p>
                  <code class="computeroutput">X::implementation_type u;</code>
                </p>
              </td>
<td>
              </td>
<td>
                <p>
                  note: <code class="computeroutput">X::implementation_type</code> has a public default
                  constructor and destructor.
                </p>
              </td>
</tr>
<tr>
<td>
                <p>
</p>
<pre class="programlisting">a.construct(b);
</pre>
<p>
                </p>
              </td>
<td>
              </td>
<td>
              </td>
</tr>
<tr>
<td>
                <p>
</p>
<pre class="programlisting">a.destroy(b);
</pre>
<p>
                </p>
              </td>
<td>
              </td>
<td>
                <p>
                  note: <code class="computeroutput">destroy()</code> will only be called on a value that
                  has previously been initialised with <code class="computeroutput">construct()</code> or
                  <code class="computeroutput">move_construct()</code>.
                </p>
              </td>
</tr>
<tr>
<td>
                <p>
</p>
<pre class="programlisting">a.move_construct(b, c);
</pre>
<p>
                </p>
              </td>
<td>
              </td>
<td>
                <p>
                  note: only required for I/O objects that support movability.
                </p>
              </td>
</tr>
<tr>
<td>
                <p>
</p>
<pre class="programlisting">a.move_assign(b, ao, c);
</pre>
<p>
                </p>
              </td>
<td>
              </td>
<td>
                <p>
                  note: only required for I/O objects that support movability.
                </p>
              </td>
</tr>
</tbody>
</table></div>
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<td align="right"><div class="copyright-footer">Copyright © 2003-2021 Christopher
      M. Kohlhoff<p>
        Distributed under the Boost Software License, Version 1.0. (See accompanying
        file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
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